Magnetic mail coding apparatus



March 14, 1967 J. R. SORRELLS ETAL MAGNETIC MAIL CODING APPARATUS Filed May 3, 1963 Paul Drake Fig.

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MAGNETIC MAIL CODING APPARATUS Filed May 5, 1963 3 Sheets-Sheet 2 Fig.5

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United States Patent Ofiiice 3,309,71 i Patented Mar. 14, 1967 3,309,711 MAIL CODKNG APZARATUS John R. Sorrells, Rockviiie, and Jacob Rahinow, Bethesda,

Md assignors, by inesne assignments, to Control Data Corporation, Minneapolis, Minn, a corporation of Minnesota Filed May 3, 1963, Ser. No. 277,896 3 Cim'rns. (Cl. 345-74) This invention relates to coding apparatus and systems, and particularly to systems for magnetically coding pieces of mail.

The enormity of the mail'handling problem faced by the US. Post Ofiice is not often understood. For instance, it may not be generally known that the main post oifice in Washington, D.C., handles an average of one and one half million pieces of mail each day with peak loading of approximately three million pieces. Furthermore, the volume of mail has been steadily increasing each year.

Automatic sorting machines have been developed to alleviate this problem. The Rabinow-Kamm U.S. Patent No. 2,901,089 discloses a sorting machine designed for handling letter mail. Machines such as this are currently being used by the US. Post Oflice. However, sorting machines are only a partial answer to the mail-handling problem. The pieces of mail must be read and coded to enable the sorting machine to function for the obvious reason that the sorting machine must be coded for (told) the correct destination of each piece of mail for the machine to know to which pocket that each letter must be sorted.

Some years ago a considerable amount of effort was expended in ascertaining the most feasible and in general, the best method of codin the pieces of mail so that each letter would carry its destination code when it is fed into the sorting machine. The J. Rabinow Patents Nos. 2,90l, 969 and 2,912,925 disclose optical coding of pieces of mail, and the Rabinow pending application Ser. No. 810,760 indicates a parallel research effort directed toward magnetic coding of pieces of mail. ()ur invention provides improvements in magnetic coding equipment for high volume coding of articles, especially pieces of mail and in general, this invention relates to subject matter similar to that of the Rabinow pending application Ser. No. 810,760.

Owing to the huge number of pieces of mail which must be handled every day by the US. Post Office, sorting speed, machine-efficiency, and cost of equipment are unusually important factors. To these ends, the concept of presorting disclosed in the Rabinow Patent No. 2,912,925 substantially doubles the effectiveness of a sorting for reasons described in that patent.

On a footing with the importance of machine-efficiency is the requirement of reasonable equipment-costs. For each sorting machine of the type disclosed in the Rabinow Patent No. 2,901,089 for example, there are one dozen input devices i.e. letter directing stations where letters are automatically presented in the view of the human operator who operates keys of a keyboard causing the letters to be directed to the proper bin (and the sorting machine correspondingly set) in synchronism with the insertion of the letters into the sorting machine. Present conservative estimates of the number of magnetic (or optical) coding devices required for only a reasonable fraction of the letter mail, is of the order of ten thousand coding stations. Again estimating conservatively, the total expense is of the order of many millions of dollars. This leads to one of the principal objectives of our invention which is to provide a magnetic coding station which is less expensive than prior magnetic coding stations and yet, which is capable of performing the functions of prior magnetic coding stations.

In comparison to a coding station like that disclosed in the Rabinow application Ser. No. 810,760 and any coding device which uses butter-storage between the code generator and the writing head, our invention achieves considerable economy by recording directly instead of 7 through a butter. in other words, when the key or keys are depressed the article is coded. When the operator has finished his manual operation, the recordation of the code is also finished. Thus, our invention eliminates a butter and any and all control circuits associated with a butter.

Accordingly, in the various embodiments of our invention we provide a conventional keyboard code generator, a recording head structure and conductive means directly connecting the code generator to the head structure.

Heretofore, buffers were used between the code generator and magnetic Writing head for several reasons. In pen-ding application Ser. No. 810,760 the buffer serves three purposes. The first is to assure synchronous motion of the letter with the modulation of the magnetic head in order to provide the desired spacing of the bits of the code recorded on the letter. Another purpose is that of a memory, since the pending application has means to verify the code immediately after it is placed on the letter. Thus, the code signal from the keyboard code generator is stored in the butter, recorded on the letter, and the recorded code is read and compared to the stored code (in the memory device). If the two codes (stored in the buffer and read from the letter) do not verify, a reject signal is provided. The third purpose is to provide unobstructed vision of the letter at the time that the keys are depressed.

In our invention the immediate verification feature is eliminated as being unnecessary, and if verification is desire-d it can be accomplished in a considerably more economical manner, as by the use of check digits, veritying codes, etc. The functions of the buffer in the RabinoW pending application are cared for by far more economical means. Further, We do not have to contend with the inertia of a conveyor, as does the apparatus in the Rabinow application. Instead, the several embodiments of our invention use a head-carriage which is preferably, but not necessarily, constructed to function in the manner very similar to the carriage of a conventional typewriter. With the comparatively low inertia of a magnetic head and its carriage we can (a) move the magnetic head (and its supporting carriage) through a fixed distance while serially recording the binary bits of the code; b) use a special multi-section recording head which concurrently records all of the bits of the code (e.g. one character at a time) while both the head and the envelope are at rest, and then move the multi-sectional head to a new position with respect to the envelope and again record the bits defining another character. Methods (a) and (b) are slightly different in that the bits defining a character are sequentially recorded in (a) and concurrently recorded in (b).

Although codes can often be recorded in transverse rows across the record (e.g. tape), there is usually not enough clear space on a piece of mail for such a recording format, and problems of skew make this method of recording very ditricult. Thus, it has been accepted as a requirement that the code bits be arranged alongside of each other in the direction of motion of the recording head or envelope. This leads to difiiculties in attempting to obtain reasonable packing density, as discussed below.

Although we can use a conventional magnetic recording head when the magnetic bits are recorded sequentially as the head moves, it is not possible to use conventional heads when recording a plurality of bits concurrently if reasonable packing density is required. The reason is that conventional heads are at least inch long (i.e. as measured in the direction of motion of the envelope or head), meaning that the bits of a code would have to be at least A inch apart. Thus, we use a special recording head with a magnetic head assembly such that bits arranged in a line parallel to head or envelope motion are reasonably closely packed, eg 30 or 40 bits to the inch.

Another object of the invention is to provide a magnetic coding system for pieces of mail, wherein a specim recording head construction and head carriage contribute to the realization of a practical instant coding system in contrast to prior coding techniques using inherently expensive buffer storage.

Other objects and features of importance will become apparent in following the description of the illustrated forms of the invention.

FIGURE 1 is a largely schematic, elevational view showing a coding station in accordance with the invention.

FIGURE 2 is a fragmentary diagrammatic view showing a modification.

FIGURE 3 is a diagrammatic view showing another modification.

FIGURE 4 is a diagrmmatic view showing a third modification.

FIGURE 4a is a fragmentary diagrammatic view similar to FIGURE 4 except for a circuit modification.

FIGURE 5 is a diagrammatic view showing another modification of our invention.

FIGURE 6 is a fragmentary top view showing the photocell and timing disc of FIGURE 5.

FIGURE 7 is a perspective view of the multi-section magnetic head structure.

FIGURE 8 is a diagrammatic view along line 8-8 of FIG. 7.

FIGURE 9 is a fragmentary elevational view schematically showing a magnetic recording of the bits defining three characters on a piece of mail.

FIGURE 1 shows one embodiment of our coding station which is more completely illustrated than the other embodiments. It is understood that many components common to the various embodiments, are not fully illustrated in the embodiments of FIGURES 2-6. The common elements and components shown in the several embodiments are identified by the same reference numerals.

FIGURE 1 shows a main frame 10 supporting an endless conveyor 12 which can be a belt, chain, etc. provided with pins 14 or the equivalent, along the length thereof. The conveyor has pulleys 16, 18 at its ends and pulley 18 is actuated by a conventional indexing motor 20 or the equivalent. The letters to be coded are fed to the conveyor (by conventional means, not shown) and moved along surfaces 22 by the conveyor pins 14 due to the indexing of the conveyor.

Keyboard code generator 24 is a conventional encoder such as the keyboard code generator manufactured by the INVAC Corporation of Natick, Massachusetts, or as disclosed and/or referred to in Patents 2,901,969; 2,912,925 or 3,104,388. All of these code generators provide an output code signal in response to the depression of one or more keys. Some code generators are parallel output devices (FIGURE 1), while others are serial output devices (FIGURE 2). Further, various keyboard code generators produce an end of character signal, while others do not. The code generator in the Rabinow Patent No. 2,912,925 has key control means to provide sorting signals, and we have shown this facility in the drawings. Typical sorting divisions are for air mail, local, outgoing, and rejected.

In FIGURE 1 code generator 24 has a parallel output on lines 26 i.e. the deprssion of one key provides concurrent outputs on the six lines 26 to define a character (as a six-bit code). Lines 26 are directly connected to a concurrent-recording, multi-section magnetic head 28 (shown in FIGURES 7, 8 and described later). When a character (six bits in the example) is recorded on the magnetic strip 30 previously sprayed or otherwise adhered to the letter, OR gate 32 detects the code by having OR gate input lines 34 connected to the individual code-conducting lines 26. Accordingly, a carriage index signal 36 is conducted as the output of OR gate 32 in order to actuate electromagnet 38. The electromagnet operates an escapement 40 which allows spring 42 to move head carriage 4-4 a predetermined distance. Escapement 40 is a conventional pivoted ratchet 46 which is spring urged in a given position and pivotedly oscillated when electromagnet 38 is pulsed. The escapement engages teeth 48 formed along the length of carriage 44, and for each cycle of the escapernent, spring 4-2 moves carriage 44 a distance cor responding to a predetermined (one or more) number of teeth 48.

The recording head 28 is secured by bracket 50 to one end of the carriage, and the entire carriage is constrained to straight line motion by means of a guide, track, etc. (not shown).

Timing presents no problem in the various forms of our invention because the electromagnet 38 is slower-acting than the magnetic recording by head 28. In other words, when a code occurs on lines 26 it is instantaneously recorded by head 28 in the magnetic strip 30 and the electromagnet 38 and escapernent ratchet respond sufiiciently slowly so that head 28 does not move until after the code has been recorded.

As mentioned above, some code generators provide a signal at the end of the code or character (if the code represents a character). With such a signal available, as diagrammatically represented by line 52, it can be used in place of lines 34, OR gate 32 and line 36, by simply connecting the end of character signal-line 52 directly to electromagnet 38.

When the operator at the code station encodes the entire message (usually an abbreviation of the destination), carriage 44 will have stepped to the right (as shown) and the operator is ready to code another letter. The operator can depress a special key (not shown) of code generator 24 to provide a signal for indexer 20, or the operator can depress one of the sorting keys 54 whose output lines control sorting gates (or the like) in a manner similar or identical to that described in the Rabinow Patent No. 2,912,925. Thus, there will be a signal on one of the sorting lines 56 which an be used to operate indexer 20 in the following manner. A plurality of conductors 58 are connected to the individual sorting-signal lines 56 and to the input terminals of OR gate 60. The output line 62 of the OR gate is connected to lines 64, 66, the former furnishing a signal for actuation of indexer 20. The signal conducted on line 62 is impressed via line 66 on solenoid 68 to return carriage 44 to an initial osition established by stop 70 which is fixed to frame 10. The force of solenoid 68 is sufficient to overcome the yielding opposition of spring 42, and the ratchet teeth 48 are designed to allow the carriage to move easily in the returndirection (as a typewriter carriage). With the return of the carriage to the initial position against stop 70 and the actuation of conveyor 12, a new envelope is presented to the view of the code station operator, and the coding apparatus is in condition to be used again.

Attention is directed to FIGURE 2 where code generator 24a provides a serial code output one line 26a. When a serial code generator is used, and we wish to record all of the bits concurrently with multi-sectional heads 28, we still use a direct recording system (no memory or storage device), but convert the serial code to a parallel code as it is conducted from code generator 24a to head 28. The code converter is made of a filling-shift register 76 which has line 26a as its input, and the output lines 78 ofthe code converter register form individual input lines or AND gates 80. The output lines 82 of the AND gates are connected to the individual sections (just as in FIGURE 1) of the multi-sectional head 28. In code conversion (from serial to parallel), gates are concurrently interrogated by the end of character signal on lines 52, 84 from code generator 24a, or by a signal derived from line 25a. This end of character signal is also used to actuate the escapement 49 via lines 52, 53.

The operation of the code-conversion feature is as follows-upon depression of a key of the code generator 24a a serial pulse code is conducted on line Elia and it ripples into code converter. The end of code signal is conducted on lines 52, 84 to simultaneously interrogate all of the gates 38 thereby enabling the gate output lines 82 to pass the binary code bits from converter register 76 over lines 82 to the individual sections of head 28. The carriage 44 is stepped a distance corresponding to the width of the sections of head 28, due to the signal on lines 52, 53. (Ratchet teeth are not drawn to scale.) \Vhen the entire message has been recorded, the indexing of conveyor 12 and the actuation of the carriage-return solenoid is precisely the same as that described in connection with FIGURE 1.

FIGURE 3 shows another modification which is the same as that of FIGURE 2 except for the means to convert the serial code to a parallel code in the direct connection between the code generator and the magnetic recording head. In this embodiment, code generator 24a provides a serial code output on line 26b to which line 85 is attached at juncture 88. Line 86 provides one information input for the group of AND gates 89. The output lines 82 of the AND gates are connected with head 28 as described in connection with FIGURE 2. The code converter in this embodiment is made of a ring counter 99 whose output lines ")2 are connected as individual inputs to the gates 81 The gatin trigger circuit for ring counter 90 is slaved to the binary pulses of the information signal on lines 251;, Sr? in the following manner; line 94 is connected to line 25b at juncture 83, and is OR gated at 96 with line 93. Line 98 is attached to line and there is an inverter 1 interposed in line 94 between OR gate and the connection of line 98 with line 94. Assuming that ring counter 99 will step only when a positive signal is applied to shift line 182, line 9:; together with the line containing inverter 10% will assure that at least one input of OR gate 3'6 will always be positive. In other words, if a positive pulse of the information signal on line 26b occurs, it will be conducted on line 9% and pass the OR gate 95. If a negative pulse occurs on line 2611 (as part of the information signal code) it will be conducted on line 33 and will not affect the OR gate, since the OR gate will pass only positive signals. But the same pulse will be inverted by inverter 1% to a positive pulse and this will pass the OR gate.

It is new deemed evident that as the information code in serial formv is conducted on lines 2611, 86 each gate Si) sees each bit, but successive gates are pulsed by the stepping of ring counter 99 from the left end (marked with an X) to the opposite end at which the ring counter automatically resets. Summarizing, when code generator 24a of FIGURE 3 is manually operated, the code is conducted in serial form to the code converter which, in this case, functions as a stepping switch to apply the bit-information to head 28 in a serial fashion (one section of the head, FIGURE 8, is pulsed at a time). However, the head and letter are at rest at this time and due to the arrangement of head sections, the code is formed in-line on the magnetic strip as picturally shown in FIG- URE 9.

FIGURE 4 shows another serial code generator 24a whose output code on line 26c is conducted directly to a conventional (single element) magnetic recording head 28a. In this embodiment we use an ordinary recording head and still obtain the desired packing density because the head carriage 44 is caused to move with respect to the letter during the time of magnetic recording. In other words, the design of escapement 40 and pitch of ratchet teeth 48 are such that the magnetic headcarriage move a predetermined distance (equal to six bits of information, for example) during the time that the bits of the magnetic code for a single character are being recorded. As in the previous embodiments carriage motion is caused by spring 42 or an equivalent means. It is pointed out that without the use of a memory device (also called a buffer) and synchronizing circuits stopping and starting the head or envelope at reasonable speeds and with acceptable accuracy is not a simple matter if the head or the envelope is indexed for every bit of the character code. It is much simpler, if not the only practical thing, to index the carriage (or envelope) a distance sufiicient to record all of the bits of one character when the bits are recorded in line (as shown in FIG- URE 9) in the direction of head motion. Thus, we have a flip flop which is set by the leading edge of the first bit of the serial code on line 260 from generator 24a. It does not matter whether the first bit of the code is negative or positive because We have line 114 attached to line 260 and it is split into lines 116 and 118 which form inputs to OR gate 120. An inverter 122 is interposed in line 116 so that the OR gate will see a positive pulse via lines 118 or 115 regardless of the pulse polarity of each bit in the code signal. The output line 112 of the flip-flop conducts a signal to operate the escapement 40, and there is a delay 124 interposed in line 260 between its juncture with line 114- and the magnetic recording head 28a. The time constant of delay 124 is equal to that of electromagnet 38 and escapement 49 so that the code signal reaches head 28:: while carriage 4 is moving under the influence of spring 42. At the end of the character, flip flop 110 is reset by an end of character signal on line 52 and if code generator 24a does not provide such a signal the flip flop 110 can be reset by various other means such as the operator depressing an additional key to provide such a signal, or the flip flop can be automatically reset (FIGURE 4a) by a signal fed back over delay line 13a, 132 from line 112, to the reset terminal of flip flop 119'. The delay 132 interposed in line 13% is used for the purpose of assuring that the electromagnet 38 will be energized for a time long enough to have the ratchet associated with the carria e 44 operate fully.

The embodiments of FIGURES 5 and 6 use a parallel code generator 24 with a code conductor 26 connected in such a manner that a serial code is impressed on a conventional single-element recording head 28a by means of conductor 133. As in the other embodiments, the code signal from code generator 2 3 is handled in a direct manner in the sense that no buffer storage is interposed between the code generator and the recording head 23a. This embodiment uses a parallel to serial converter composed of a set of AND gates 134. Each AND gate has one of the lines 26 as one input, and the only other input to each AYD gate 134- is conducted on one of the lines 136. Lines 135 are connected to the output terminals of ring counter 138 which is stepped in synchronism with the horizontal motion of carriage 44, described later. The output lines 140 from the set of AND gates 134 are OR gated at 142, and the output of the OR gate is conducted on the previously mentioned serialccde conductor 133 to the recording head 28a. Thus, when a key of code generator 24 is depressed, the code bits are concurrently conducted on lines 26 to gates 134. The gates 134 are sequentially interrogated as ring coun ter 138 steps from the rest position to the end, at which time the rin counter automatically resets to prepare for another cycle of operation.

OR gate 144 has a plurality of input lines 146 which are connected to the individual code lines 26. Thus, OR gate detects the code and provides a signal on the OR gate output line 148 to set flip flop 150 (which is reset after a delay as in FIGURE 4a). In turn, the output of the flip flop 159 conducted on line 152 energizes electromagnet 38 to operate the escapement 40. As in the other forms of our invention, when the escapement 40 is actuated spring 42 moves the head carriage 44 a predetermined distance sufiicient to record the bits defining a single character. During this motion of the carriage, a sync pulse disc 160 is rotated in synchronisrn therewith. Rotation can be imparted to the disc in a number of ways, one of which is to have a rack 162 attached to carriage 44- and a pinion 164 engaging the rack, attached to disc 160, or to a common shaft to which the pinion and disc are secured. Disc 1166 is apertured, and the gear ratio is such that one aperture will intercept a light beam (FIGURE 6) for each bit of a character which is to be recorded. For instance, for a six bit code, six apertures intercept the light path for each operation of the escapement 40.

The light path intercepted by the disc and its apertures, is established by light source 170' (FIGURE 6), an optional lens 172 to focus the light on one surface of disc 160, and a photocell 174 facing the opposite surface of the disc. The output line 176 of the photocell has an amplifier 178 interposed therein, and the amplified outputs are conducted to ring counter 138 as shift pulses for the counter. The design of amplifier 178 is such that every time the photocell 174 detects the light source through one of the disc apertures, a pulse (or other signal) is provided to step ring counter in synchronism with the horizontal movement of the head carriage 23a.

Attention is directed to FIGURES 7 and 8 showing the multi-section magnetic recording (and reading head. Briefly, magnetic recording for computer or computerline systems almost invariably uses a multitrack arrangement where a1 lof the bits defining a single character are recorded in a row transverse to the direction of motion of the tape. This recording technique is required in computer systems for high speed operation. It would not be possible, with conventional heads to even approach the desired packing density of thirty bits per inch if the bits were recorded in-line i.e. alongside of one another in the direction of motion of the magnetic strip 30 or motion of the heads if the heads are movable. The reason is that a conventional magnetic recording head has considerable length measured in a direction perpendicular to the gap of the head. Commercially available magnetic heads are generally from A to A of an inch along and above defined dimension. Therefore, it two heads are placed alongside of each other, the best that can possibly be expected is that the code bits will have a spacing (in the direction of motion of the magnetic tape) of /4 of an inch. On the other hand, heads 28 have been constructed (FIGURES 7 and 8) where the critical length measured in the direction of motion of the tape) is only .030 of an inch, and there is no reason why this dimension cannot be reduced to .015 of an inch or less.

The small head-length is achieved by using long flat substantially U-shaped members 188 as the iron structure of a typical head section and winding a coil 190 between the sides of the U-shaped structure. The extremeties of structure 188 form the flux gap. Magnetic shields for magnetic pulses), for example flat strips 192 of copper, are located between adjacent head sections. The entire assembly may be potted in potting material or otherwise suitably encapsulated.

We pointed out various advantages of recording characters in transverse row across the tape when one is recording infiormation for computer usage. However, it is not practical to record code information on letter mail in the same manner as the front of the letter cannot be severely defaced because of the address, return address and postage thereon. A thin stripe 30 along the lower edge is about all that can reasonably be tolerated, and one and possibly two or three (not shown) tracks of code information can be recorded in strip 33. Also, the strip 30 can be transparent or semi-transparent as disclosed in the Rabinow application Ser. No. 810,760.

it is now understood that the previous descriptions are given by way of examples only and various charges, modifications, alterations, etc. may be resorted to Without departing from the protection of the following claims. For example, while we refer principally to letter mail, we can code other articles as packages, checks, cards, documents, containers and others.

We claim:

1. Coding apparatus to magnetically code a postal article at a coding station, said apparatus comprising a conveyor for the article, a transducer carriage adapted to be rectilinearly indexed, a transducer on said carriage, said transducer including a group of head structures having parallel gaps arranged perpendicular to the direction of transducer carriage movement, said gaps being spaced approximately 0.03 inch in the direction of transducer carriage movement, each head structure being capable of recording a discrete bit of independently of the adjacent head structures, and there being a number of head structures in the group sufiicient to record a code which corresponds to a character, a code signal generator for providing code signals corresponding to the bits which define the code of said character, means including conductors to conduct the individual code signals to the respective head structures of said transducer while said carriage is at rest and in a manner such as for the character code each head has one bit signal conductor connected therewith, and means effective after the code for said character is transduced by said transducer for indexing said transducer carriage along said station a distance at least equal to the distance between the first and last gap of the transducer thereby positioning said transducer relative to the article for the coding of another character.

2. The subject matter of claim 1 wherein said carriage indexing means are electrically actuated, and the electrical signal to actuate said indexing means is derived from said code signal generator.

3. The subject matter of claim 2 and carriage return means responsive to a signal derived from said code generator for returning said carriage to a predetermined position upon completion of the coding of the article.

References Cited by the Examiner UNITED STATES PATENTS 3,040,323 6/1962 Brenner et al. 346-74 3,173,533 3/1965 Zuck 2091l1.5 X 3,196,450 7/1965 Chapin 346-74 BERNARD KONICK, Primary Examiner.

A. I, NEUSTADT, Assistant Examiner, 

1. CODING APPARATUS TO MAGNETICALLY CODE A POSTAL ARTICLE AT A CODING STATION, SAID APPARATUS COMPRISING A CONVEYOR FOR THE ARTICLE, A TRANSDUCER CARRIAGE ADAPTED TO BE RECTILINEARLY INDEXED, A TRANSDUCER ON SAID CARRIAGE, SAID TRANSDUCER INCLUDING A GROUP OF HEAD STRUCTURES HAVING PARALLEL GAPS ARRANGED PERPENDICULAR TO THE DIRECTION OF TRANSDUCER CARRIAGE MOVEMENT, SAID GAPS BEING SPACED APPROXIMATELY 0.03 INCH IN THE DIRECTION OF TRANSDUCER CARRIAGE MOVEMENT, EACH HEAD STRUCTURE BEING CAPABLE OF RECORDING A DISCRETE BIT OF INDEPENDENTLY OF THE ADJACENT HEAD STRUCTURES, AND THERE BEING A NUMBER OF HEAD STRUCTURES IN THE GROUP SUFFICIENT TO RECORD A CODE WHICH CORRESPONDS TO A CHARACTER, A CODE SIGNAL GENERATOR FOR PROVIDING CODE SIGNALS CORRESPONDING TO THE BITS WHICH DEFINE THE CODE OF SAID CHARACTER, MEANS INCLUDING CONDUCTORS TO CONDUCT THE INDIVIDUAL CODE SIGNALS TO THE RESPECTIVE HEAD STRUCTURES OF SAID TRANSDUCER WHILE SAID CARRIAGE IS AT REST AND IN A MANNER SUCH AS FOR THE CHARACTER CODE EACH HEAD HAS ONE BIT SIGNAL CONDUCTOR CONNECTED THEREWITH, AND MEANS EFFECTIVE AFTER THE CODE FOR SAID CHARACTER IS TRANSDUCED BY SAID TRANSDUCER FOR INDEXING SAID TRANSDUCER CARRIAGE ALONG SAID STATION A DISTANCE AT LEAST EQUAL TO THE DISTANCE BETWEEN THE FIRST AND LAST GAP OF THE TRANSDUCER THEREBY POSITIONING SAID TRANSDUCER RELATIVE TO THE ARTICLE FOR THE CODING OF ANOTHER CHARACTER. 